Failed O-ring leads to loss of power

The student pilot, accompanied by a flight instructor, were practicing takeoffs and landings in a Piper Cherokee at the airport in Winder, Ga., when the airplane’s engine lost all power.

The CFI took the controls and attempted to glide to a runway. The airplane was not aligned with the runway centerline and went off the edge of the pavement and into a bog.

Following the accident, the engine was started, but it only ran for about 10 seconds and then quit.

Further examination revealed that, when the engine ran briefly, fuel leaked from the inlet side of the engine-driven fuel pump due to a cracked fuel pump line fitting O-ring seal.

The airplane’s most recent annual inspection had been completed about two months before the accident. At that time, the engine had accumulated about 1,578 hours since its last overhaul about 16 years before the accident, which exceeded the engine manufacturer’s recommended time interval for overhaul of every 2,000 hours or 12 years, whichever came first.

The airplane had been operated for about 15 hours since its most recent annual inspection, but investigators noted that a cracked O-ring seal might not be detected during an annual inspection if the engine was not leaking fuel at that time.

The NTSB attributed the accident to the total loss of engine power due to a cracked fuel pump line fitting O-ring seal at the inlet to the engine driven fuel pump. Contributing to the accident was the failure of the aircraft operator to comply with the engine manufacturer’s recommended time interval for overhaul.